. Right in the middle near Dunkeld they built Inchtuthil- a full scale legionary fortress. That was possibly the place called "Victoria" on Ptolemy's 2nd century map.
Whether less than 30,000 Caledonians were slaughtered or not, the evidence shows Mons Graupius was a triumph for Rome and the Caledonians got thoroughly beaten. The effect on the cultur.